The present Patent of Invention relates to a new electric heating device to release active substances that, in addition to the function for which it was designed, affords a number of advantages discussed below and others that are inherent in its organisation and construction.
Several state-of-the-art devices exist that are used for evaporating aromatic or active substances, for instance insecticides or fragrances, equipped with electric heating designed to nonpermanently release the active substances, only in case of need.
The aromatic or active substances can thus be supported by solid materials or be liquid.
Several state-of-the-art devices are known, for instance disclosed in registrations such as European Patent 90121288.6, Utility Model no. 9203290/7, Utility Model 9501364/4, and others.
Due to their design, state-of-the-art devices have two drawbacks worthy of note, one of which is the large quantity of constituent parts they have, with the ensuing costs derived from the moulding or manufacturing process of said parts. A second drawback is due to the substantial degree of difficulty the mounting process represents, which poses problems in connection with an automated mounting.
That is why said heating elements are expensive and hence barely competitive as compared with other conventional apparatus designed for similar purposes.
Another drawback of the state of the art is the absence of specific means devised for an easy, optional connection of additional elements, such as timers, adjusters, and others.
The company applying for the present Patent of Invention has used its expertise in the manufacture of devices of this kind, to devise heating means to heat a body having a round shape, and provided with a hole to receive the wick carrying a means to be evaporated.
A first object of the invention is to achieve an arrangement of the kind aforesaid, designed so as to have a small number of constituent parts, which are sandwiched together in order thereby to provide a fully automatic assembly, which results in substantial costs savings.
A second object of the invention is to provide said device with heating means that use up little electricity in operation and produce a homogeneous heating, irrespective of the supply voltage.
This second object is achieved using a PTC element for the heating to render the quantity of electric power released and the supply voltage independent from each other, due to the peculiar PTC characteristics, which self-stabilise and control temperature within a very wide voltage field.
The invention successfully solves the problem that usually arises when PTC elements are employed, for, being very small components, approximately with a diameter of eight millimetres and a thickness of three millimetres, the transfer of heat energy is locally limited.
Because in the device subject of the invention, the round body, which receives the means to be evaporated, must be heated as uniformly as possible, a special shape and material is used for the electrodes, which are ring-shaped in order to encircle the hole that is to be heated, and made of a material of good heat-conducting characteristics.
This organisation allows a single PTC element to be used to supply power with the ensuing economic savings.
In spite of the power concentration at the PTC location, a very uniform heating is achieved to meet requirements, given the characteristic that the electrodes fully surround the hole that is to be heated.
The improvements in accordance with the present Patent of Invention offer the advantages described hereinbefore and others that will follow easily from the embodiment of a device provided with electric heating having the said improvements that is described hereinafter in further detail for an easier understanding of the characteristics set out above, concurrently referring to a number of details, to which end a number of drawings are attached to the present specification which represent a practical embodiment of the present invention, merely as an example that is not intended to limit the same.